Shepherd writeup

(1) What type of RFC is being requested (BCP, Proposed Standard, 
Internet Standard, Informational, Experimental, or Historic)?

    Internet Standard

  Why is this the proper type of RFC?

    It defines the actual mechanism and propose a default algorithm for
    the SIP? Overload Control Mechanism

  Is this type of RFC indicated in the title page header?


(2) The IESG approval announcement includes a Document Announcement 
Write-Up. Please provide such a Document Announcement Write-Up. Recent 
examples can be found in the "Action" announcements for approved 
documents. The approval announcement contains the following sections:

    Technical Summary:
    Overload occurs in Session Initiation Protocol (SIP) networks when
    SIP servers have insufficient resources to handle all SIP messages
    they receive.  Even though the SIP protocol provides a limited
    overload control mechanism through its 503 (Service Unavailable)
    response code, SIP servers are still vulnerable to overload.  This
    document defines the protocol for communicating overload information
    between SIP servers and clients, so that clients can reduce the
    volume of traffic sent to overloaded servers, avoiding congestion
    collapse and increasing useful throughput.

Working Group Summary:

    This document was originally started by an ad-hoc Design Team within
    the SIPPING wg. The document was then adopted by the SIP  Overload
    Control WG once it has been created.
    There has been 13 versions of the document of the document since it
    has?been adopted as WG item, and the document has passed two
    WGLC?one in March 2012
    and a second one in February 2013
    All the issues and the feedback raised have been addressed, and the
    wg is now happy with the status.

Document Quality:
Are there existing implementations of the protocol?

    I am not aware of any.

Have a significant number of vendors indicated their plan to implement 
the specification?

    Yes, all the major vendors have indicated they have a plan to
    implement it.
    Moreover also 3GPP is supporting it and it will be referenced in its

Are there any reviewers that merit special mention as having done a 
thorough review, e.g., one that resulted in important changes or a 
conclusion that the document had no substantive issues? If there was a 
MIB Doctor, Media Type or other expert review, what was its course 
(briefly)? In the case of a Media Type review, on what date was the 
request posted?


Who is the Document Shepherd?

    Salvatore Loreto <>

Who is the Responsible Area Director?

    Richard Barnes <>

(3) Briefly describe the review of this document that was performed by 
the Document Shepherd. If this version of the document is not ready for 
publication, please explain why the document is being forwarded to the IESG.

    The document is clear and very well written.

(4) Does the document Shepherd have any concerns about the depth or 
breadth of the reviews that have been performed?

    I don't have any concern about the document. The process has been a
    bit slow but the document is really solid now, it has passed 2 WGLCs
    that have?generated several comments, feedback and the authors have
    discussed and?eventually fixed all of them.

(5) Do portions of the document need review from a particular or from 
broader perspective, e.g., security, operational complexity, AAA, DNS, 
DHCP, XML, or internationalization? If so, describe the review that took 


(6) Describe any specific concerns or issues that the Document Shepherd 
has with this document that the Responsible Area Director and/or the 
IESG should be aware of? For example, perhaps he or she is uncomfortable 
with certain parts of the document, or has concerns whether there really 
is a need for it. In any event, if the WG has discussed those issues and 
has indicated that it still wishes to advance the document, detail those 
concerns here.

    I don't have any particular concern with this document.

(7) Has each author confirmed that any and all appropriate IPR 
disclosures required for full conformance with the provisions of BCP 78 
and BCP 79 have already been filed. If not, explain why?

(8) Has an IPR disclosure been filed that references this document?


(9) How solid is the WG consensus behind this document? Does it 
represent the strong concurrence of a few individuals, with others being 
silent, or does the WG as a whole understand and agree with it?

    This document has received unanimous consensus from all the wg
    participants.?Even if the number of participants in the wg has been
    always quite low.

(10) Has anyone threatened an appeal or otherwise indicated extreme 
discontent? If so, please summarise the areas of conflict in separate 
email messages to the Responsible Area Director. (It should be in a 
separate email because this questionnaire is publicly available.)


(11) Identify any ID nits the Document Shepherd has found in this 
document. (See and the Internet-Drafts 
Checklist). Boilerplate checks are not enough; this check needs to be 

    I haven't identified any nit.

(12) Describe how the document meets any required formal review 
criteria, such as the MIB Doctor, media type, and URI type reviews.
does not apply.
(13) Have all references within this document been identified as either 
normative or informative?


(14) Are there normative references to documents that are not ready for 
advancement or are otherwise in an unclear state? If such normative 
references exist, what is the plan for their completion?

    No. All the normative references are already RFCs.

(15) Are there downward normative references references (see RFC 3967)? 
If so, list these downward references to support the Area Director in 
the Last Call procedure.


(16) Will publication of this document change the status of any existing 
RFCs? Are those RFCs listed on the title page header, listed in the 
abstract, and discussed in the introduction? If the RFCs are not listed 
in the Abstract and Introduction, explain why, and point to the part of 
the document where the relationship of this document to the other RFCs 
is discussed. If this information is not in the document, explain why 
the WG considers it unnecessary.


(17) Describe the Document Shepherd's review of the IANA considerations 
section, especially with regard to its consistency with the body of the 
document. Confirm that all protocol extensions that the document makes 
are associated with the appropriate reservations in IANA registries. 
Confirm that any referenced IANA registries have been clearly 
identified. Confirm that newly created IANA registries include a 
detailed specification of the initial contents for the registry, that 
allocations procedures for future registrations are defined, and a 
reasonable name for the new registry has been suggested (see RFC 5226).

    The IANA consideration section is consistent with the body of the
    document. All? the four new parameters for the SIP Via header for
    overload control are associated with the appropriate reservations in
    IANA registries.
    The wg has also discussed about the opportunity to establish for the
    "oc-algo" parameter
    ), but there is a wg consensus on not to do it

(18) List any new IANA registries that require Expert Review for future 
allocations. Provide any public guidance that the IESG would find useful 
in selecting the IANA Experts for these new registries.
(19) Describe reviews and automated checks performed by the Document 
Shepherd to validate sections of the document written in a formal 
language, such as XML code, BNF rules, MIB definitions, etc.